Antibodies to GAD65 Epitopes at Diagnosis and Over the First 10 years of Clinical Type 1 Diabetes Mellitus

Antibodies to glutamate decarboxylase (GAD65Ab) may persist, and their titres even increase after the clinical onset of type 1 diabetes. To characterize this phenomenon in detail, we analysed sequentially antibodies to GAD65 epitope clusters in a radio‐binding assay in patients with type 1 diabetes. Serum samples were taken at diagnosis and 2, 5 and 10 years later from 50 young patients who had tested positive for GAD65Ab at least once during observation. The levels of GAD65Ab peaked in 21 patients after diagnosis. Antibodies to the middle region of GAD65 (GAD65‐M‐Ab, 88%) were more common at diagnosis than antibodies to the C‐terminal (GAD65‐C‐Ab, 68%, P